Sometimes I wonder whether Kaguya/Yachiyo is secretely super-anxious about Iroha's lifespan. 8 millenia to this point? Just a world record pace GTNH speedrun. But after that, everything is uncertain even to her, and imagine waiting this long for such a short sliver of happiness in relation, just for an eternity of mourning after...
I like to think that if Iroha can spend a decade figuring out android bodies, Yachiyo could've spent eight millennia figuring out brain upload tech. If her bamboo ship's got the processing power for her to pull off mass-duplication shenanigans, surely it has room to spare for an Iroha~